Cellulose-based products made from cellulosic fibers, chips and shavings make up a significant portion of the building product market because they are cost effective, and easy to work with. Cellulose-based products provide structural support, act as roofing substrates, and even dampen unwanted noise. Unfortunately, untreated cellulose-based products are particularly susceptible to flame and thermal damage because they are composed of flammable fibers or particles. A number of coatings have been developed to reduce the flammability of such materials, but too often these methods are inadequate at providing fire-retardancy, are too expensive, produce toxic-off gas or smoke under continued exposure to flame, or have some other shortcoming. A need exists for a cost effective, thin ceramic coating for cellulose-based materials which can impart Class A flame resistance.
For example, U.S. Pat. No. 5,035,851, issued to Dimanshtaeyn describes a fire-resistant coating comprising: a silicate, a clay and some inorganic materials (e.g. a borate) which can be used to coat metals, woods and foamed polymeric materials to impart some degree of fire resistance thereto. This is a complicated and expensive solution and acceptable resistance to fire is not always achieved.
A need exists for fire-retardant coating for building materials that is cost effective, non toxic and which provides superior fire-retardancy.